#include "radar_screen.h"
#include "config.h"
#include "aircraft.h"
#include "aircraft_table.h"
#include "airline_lookup.h"
#include "aircraft_details.h"
#include "radar_math.h"
#include "units.h"
#include "settings_store.h"
#include "led_alert.h"
#include "location_manager.h"
#include "sun_times.h"
#include "world_map.h"
#include "airline_filter.h"
#include "aircraft_watchlist.h"
#include "i18n.h"
#include "menu_stars.h"
#include "touch_input.h"
#include <math.h>
#include <time.h>
#include <algorithm>

namespace RadarScreen {

namespace {
    struct Rect {
        int16_t x, y, w, h;
        bool contains(int16_t px, int16_t py) const {
            return px >= x && px < x + w && py >= y && py < y + h;
        }
    };

struct Layout {
int16_t cx, cy, radius;
        Rect rangeBtn;
        Rect listBtn;
        Rect altBtn;
        Rect searchBtn;
        Rect helpBtn;
        int16_t infoTop;
    };

    constexpr int16_t INFO_BAR_H = 64;
// Additional height for the second legend row (ground vehicle
    // marker explanation), only reserved when ground vehicles are actually
    // displayed (SettingsStore::hideGroundVehicles() == false) -
    // otherwise the info bar stays exactly as tall as before and the
    // radar circle keeps its usual size.
    constexpr int16_t INFO_BAR_GROUND_ROW_H = 18;

    int16_t infoBarHeight() {
        return SettingsStore::hideGroundVehicles() ? INFO_BAR_H : (int16_t)(INFO_BAR_H + INFO_BAR_GROUND_ROW_H);
    }

Layout computeLayout(int16_t top) {
        Layout L;
        L.infoTop = Config::SCREEN_HEIGHT - infoBarHeight();
        constexpr int16_t TOP_LABEL_MARGIN = 10;
        int16_t maxRadiusByWidth = Config::SCREEN_WIDTH / 2 - 6;
        int16_t maxRadiusByHeight = (L.infoTop - top - TOP_LABEL_MARGIN) / 2 - 6;
        L.radius = min(maxRadiusByWidth, maxRadiusByHeight);
        L.cx = Config::SCREEN_WIDTH / 2;
        L.cy = top + L.radius + 6 + TOP_LABEL_MARGIN;
L.rangeBtn = {(int16_t)(Config::SCREEN_WIDTH - 72), (int16_t)(L.infoTop + 4), 64, 22};
        L.listBtn  = {128, (int16_t)(L.infoTop + 4), 36, 22};
        L.altBtn   = {88, (int16_t)(L.infoTop + 4), 36, 22};
        L.searchBtn = {48, (int16_t)(L.infoTop + 4), 36, 22};
        L.helpBtn   = {8, (int16_t)(L.infoTop + 4), 36, 22};
        return L;
    }

// +22px compared to the previous value (264) for the new route line (see
    // drawDetailPanel()) - only affects the size of the detail panel
    // overlay, not the normal radar layout (computeLayout() above
    // only depends on infoBarHeight(), not
    // DETAIL_PANEL_H).
    constexpr int16_t DETAIL_PANEL_H = 286;

    struct HitPoint {
        int16_t x, y;
        bool valid;
        char hex[7];
        char callsign[9];
        uint16_t color;
        float headingDeg;
        float distanceKm;
        bool isEmergency;
        bool isWatched;
        bool isGroundVehicle;
        bool isRotorcraft;
        bool isHeavy;
    };
    constexpr uint8_t MAX_HIT_POINTS = Config::MAX_TRACKED_AIRCRAFT;
    HitPoint hitPoints[MAX_HIT_POINTS];

    char selectedHex[7] = {0};

    uint32_t lastEmptyTapMs = 0;
    int16_t lastEmptyTapX = -1000;
    int16_t lastEmptyTapY = -1000;
    constexpr uint32_t DOUBLE_TAP_MS = 400;
    constexpr int16_t DOUBLE_TAP_RADIUS = 25;

    bool ledBlinkOn = true;

// "Empty Sky" timer: remembers when at least one
    // aircraft was last visible (after all filters) - namespace-wide instead of
    // local to render(), since tick() (see there) needs the value on every tick
    // (every 80ms) to count up the seconds smoothly,
    // instead of only every few seconds on a render() call.
    uint32_t lastAircraftSeenMs = millis();

// Used by the detail panel marquee (LineMarquee in drawDetailPanel)
    // for scrolling route text.
    constexpr uint32_t INFO_MARQUEE_STEP_MS = 200;

    String infoMarqueeWindow(TFT_eSPI& tft, const String& src, int32_t startIdx, int16_t maxWidth) {
        String s = src.substring(startIdx);
        while (s.length() > 1 && tft.textWidth(s) > maxWidth) {
            s.remove(s.length() - 1);
        }
        return s;
    }

    bool isEmergencySquawk(const char* squawk) {
        for (uint8_t i = 0; i < Config::EMERGENCY_SQUAWK_COUNT; i++) {
            if (strcmp(squawk, Config::EMERGENCY_SQUAWKS[i]) == 0) return true;
        }
        return false;
    }

    float sweepAngleDeg = 0.0f;
    float prevSweepAngleDeg = -1.0f;
    constexpr float SWEEP_DEGREES_PER_SEC = 45.0f;

// Same logic as main.cpp::isNightDimHours() - night = between
    // sunset and sunrise at the active location (see
    // sun_times.h), with fallback to a fixed 22:00-06:00 window
    // as long as location/time are not yet known. Deliberately
    // duplicated instead of shared, see CLAUDE.md convention ("each screen
    // independently runnable, no shared module for such
    // small items").
    bool isNightHours() {
        time_t now = time(nullptr);
        if (now <= 8 * 3600 * 2) return false; // time not yet synced via NTP

        struct tm tmNow;
        localtime_r(&now, &tmNow);

        double lat = 0, lon = 0;
        LocationManager::getHomeLocation(lat, lon);
        if (lat != 0.0 || lon != 0.0) {
            SunTimes::Result sun = SunTimes::compute(lat, lon, tmNow.tm_year + 1900, tmNow.tm_mon + 1,
                                                      tmNow.tm_mday, LocationManager::utcOffsetSeconds());
            if (sun.valid) {
                if (sun.alwaysDay) return false;
                if (sun.alwaysNight) return true;
                float hourNow = tmNow.tm_hour + tmNow.tm_min / 60.0f;
                return (hourNow < sun.sunriseHour) || (hourNow >= sun.sunsetHour);
            }
        }

        int hour = tmNow.tm_hour;
        return (hour >= 22 || hour < 6);
    }

// Only active when the user has enabled night dimming (Menu > System)
    // AND we are currently in the night window - the same setting that otherwise
    // only dims the backlight, now additionally also dims the
    // radar colors (aircraft markers + sweep line), so the display
    // is less glaring overall at night.
    bool nightDimActiveNow() {
        return SettingsStore::nightDimmingEnabled() && isNightHours();
    }

// Color by altitude - dimmed (darker green/olive) during
    // night dimming.
    //
    // The red altitude level is deliberately NOT dimmed: the previous
    // dimmed tone (160,30,0) looked orange-brown instead of red
    // on the display and was therefore no longer clearly distinguishable
    // from the yellow level. Red therefore remains the pure TFT_RED tone
    // day and night.
    uint16_t colorForAltitude(TFT_eSPI& gfx, int32_t altFt) {
        bool dim = nightDimActiveNow();
        if (altFt < Config::COLOR_LOW_ALT_THRESHOLD_FT)
            return dim ? gfx.color565(0, 160, 0) : TFT_GREEN;
        if (altFt < Config::COLOR_MID_ALT_THRESHOLD_FT)
            return dim ? gfx.color565(160, 160, 0) : TFT_YELLOW;
        return TFT_RED;
    }

    uint16_t sweepLineColor(TFT_eSPI& gfx) {
        return nightDimActiveNow() ? gfx.color565(0, 110, 0) : TFT_GREEN;
    }

// Fixed blue color for ground vehicle markers (ADS-B emitter category
    // "C*", e.g. airport vehicles) - deliberately independent of
    // colorForAltitude(), since ground vehicles are practically always at 0ft
    // and would otherwise have the same color as low-flying aircraft,
    // which would unnecessarily complicate the visual distinction
    // (square vs. circle). Dimmed during night dimming, same pattern as
    // colorForAltitude().
    uint16_t colorForGroundVehicle(TFT_eSPI& gfx) {
        return nightDimActiveNow() ? gfx.color565(0, 0, 160) : TFT_BLUE;
    }

// Shows the BEARING (not to be confused with the heading)
    // to the currently selected aircraft: a thin, dotted line from the
    // radar center to the circle edge in the direction of bearingDeg, plus the degree number
    // directly outside the ring. Helps to actually find the aircraft
    // in the sky ("look in this direction"). Only relevant for the moment
    // of drawing - on the next sweep tick/redraw it is automatically
    // erased and redrawn by the normal background redraw.
    void drawBearingIndicator(TFT_eSPI& gfx, const Layout& L, float bearingDeg) {
        double rad = bearingDeg * PI / 180.0;
        double s = sin(rad), c = cos(rad);

// Dotted line: short segments instead of a solid line,
    // so it visually differs from the compass cross lines and rings
    // and does not look like a permanent UI element.
        constexpr uint8_t DOT_COUNT = 10;
        for (uint8_t i = 0; i < DOT_COUNT; i++) {
            if (i % 2 != 0) continue; // only draw every second segment
            float t0 = (float)i / DOT_COUNT;
            float t1 = (float)(i + 1) / DOT_COUNT;
            int16_t x0 = L.cx + (int16_t)lround(t0 * L.radius * s);
            int16_t y0 = L.cy - (int16_t)lround(t0 * L.radius * c);
            int16_t x1 = L.cx + (int16_t)lround(t1 * L.radius * s);
            int16_t y1 = L.cy - (int16_t)lround(t1 * L.radius * c);
            gfx.drawLine(x0, y0, x1, y1, TFT_WHITE);
        }

// Bearing degree just outside the ring, at the point where the bearing
        // line intersects the circle edge. The radius circle uses almost the full
        // screen width (see computeLayout(): only 6px margin) - a label
        // outside the ring would extend beyond the visible area
        // for east/west bearings. Therefore: clamp label position to
        // screen boundaries instead of blindly following the angle.
        int16_t labelX = L.cx + (int16_t)lround((L.radius + 10) * s);
        int16_t labelY = L.cy - (int16_t)lround((L.radius + 10) * c);
        labelX = constrain(labelX, (int16_t)14, (int16_t)(Config::SCREEN_WIDTH - 14));
        labelY = constrain(labelY, (int16_t)10, (int16_t)(L.cy + L.radius + 8));
        char buf[6];
        snprintf(buf, sizeof(buf), "%.0f", bearingDeg);
        gfx.setTextDatum(MC_DATUM);
        gfx.setTextColor(TFT_WHITE, TFT_BLACK);
        gfx.drawString(buf, labelX, labelY);
        gfx.setTextDatum(TL_DATUM);
    }

// Short course line in flight direction (headingDeg) WITH arrowhead at the end -
    // a plain line without a tip was not clearly readable (not recognizable
    // which end is "front"). The tip consists of two short strokes
    // that branch diagonally outward just before the line tip (classic
    // chevron/arrowhead symbol, as typical in ATC radar displays).
    void drawAircraftMarker(TFT_eSPI& gfx, int16_t x, int16_t y, float headingDeg, uint16_t color) {
        gfx.fillCircle(x, y, 5, color);

        double rad = headingDeg * PI / 180.0;
        int16_t dx = (int16_t)(sin(rad) * 10);
        int16_t dy = (int16_t)(-cos(rad) * 10);
        int16_t tipX = x + dx;
        int16_t tipY = y + dy;
        gfx.drawLine(x, y, tipX, tipY, color);

// Arrowhead: two short strokes from the tip, each folded back 150 degrees
        // to the course line (i.e. slightly pointing "backward",
        // as is common for an arrowhead "^").
        constexpr double WING_ANGLE_RAD = 150.0 * PI / 180.0;
        constexpr int16_t WING_LEN = 4;
        double wing1 = rad + WING_ANGLE_RAD;
        double wing2 = rad - WING_ANGLE_RAD;
        int16_t w1x = tipX + (int16_t)(sin(wing1) * WING_LEN);
        int16_t w1y = tipY + (int16_t)(-cos(wing1) * WING_LEN);
        int16_t w2x = tipX + (int16_t)(sin(wing2) * WING_LEN);
        int16_t w2y = tipY + (int16_t)(-cos(wing2) * WING_LEN);
        gfx.drawLine(tipX, tipY, w1x, w1y, color);
        gfx.drawLine(tipX, tipY, w2x, w2y, color);
    }

// Separate marker for ground vehicles (ADS-B category "C*") - a
    // filled square instead of circle+arrowhead, so they are clearly
    // distinguishable from real aircraft on the radar (heading/course is
    // also usually not meaningful for ground vehicles).
    void drawGroundVehicleMarker(TFT_eSPI& gfx, int16_t x, int16_t y, uint16_t color) {
        constexpr int16_t HALF = 4;
        gfx.fillRect((int16_t)(x - HALF), (int16_t)(y - HALF), (int16_t)(2 * HALF), (int16_t)(2 * HALF), color);
    }

// Separate marker for helicopters (ADS-B emitter category "A7" =
    // Rotorcraft) - a filled circle with a solid rotor cross instead of
    // an arrowhead, since helicopters in hover have no meaningful
    // "forward" course like a fixed-wing aircraft (same reasoning as the
    // ground vehicle marker, which for the same reason also
    // does without a course line).
    void drawHelicopterMarker(TFT_eSPI& gfx, int16_t x, int16_t y, uint16_t color) {
        constexpr int16_t ROTOR_LEN = 8;
        gfx.fillCircle(x, y, 4, color);
        gfx.drawLine((int16_t)(x - ROTOR_LEN), y, (int16_t)(x + ROTOR_LEN), y, color);
        gfx.drawLine(x, (int16_t)(y - ROTOR_LEN), x, (int16_t)(y + ROTOR_LEN), color);
    }

// Separate marker for "Heavy" aircraft (ADS-B emitter category "A5" -
    // aircraft over 136t maximum takeoff weight, e.g. A380/B747/B777/A330).
    // Same structure as drawAircraftMarker() (circle + course line with
    // arrowhead), but with a larger circle and an additional thin
    // outer ring - recognizable at first glance as "larger/heavier",
    // without introducing a completely new shape language. The color remains
    // the usual altitude color (colorForAltitude()) - the shape conveys
    // "Heavy", not an alarm/conspicuity state.
    void drawHeavyMarker(TFT_eSPI& gfx, int16_t x, int16_t y, float headingDeg, uint16_t color) {
        gfx.fillCircle(x, y, 6, color);
        gfx.drawCircle(x, y, 8, color);

        double rad = headingDeg * PI / 180.0;
        int16_t dx = (int16_t)(sin(rad) * 10);
        int16_t dy = (int16_t)(-cos(rad) * 10);
        int16_t tipX = x + dx;
        int16_t tipY = y + dy;
        gfx.drawLine(x, y, tipX, tipY, color);

        constexpr double WING_ANGLE_RAD = 150.0 * PI / 180.0;
        constexpr int16_t WING_LEN = 4;
        double wing1 = rad + WING_ANGLE_RAD;
        double wing2 = rad - WING_ANGLE_RAD;
        int16_t w1x = tipX + (int16_t)(sin(wing1) * WING_LEN);
        int16_t w1y = tipY + (int16_t)(-cos(wing1) * WING_LEN);
        int16_t w2x = tipX + (int16_t)(sin(wing2) * WING_LEN);
        int16_t w2y = tipY + (int16_t)(-cos(wing2) * WING_LEN);
        gfx.drawLine(tipX, tipY, w1x, w1y, color);
        gfx.drawLine(tipX, tipY, w2x, w2y, color);
    }

    void printLineTruncated(TFT_eSPI& gfx, int16_t x, int16_t y, int16_t maxWidth, const String& text) {
        String s = text;
        if (gfx.textWidth(s) > maxWidth) {
            while (s.length() > 1 && gfx.textWidth(s + "...") > maxWidth) {
                s.remove(s.length() - 1);
            }
            s += "...";
        }
        gfx.setCursor(x, y);
        gfx.print(s);
    }

    void drawButton(TFT_eSPI& gfx, const Rect& r, const String& label) {
        gfx.fillRoundRect(r.x, r.y, r.w, r.h, 4, TFT_BLACK);
        gfx.drawRoundRect(r.x, r.y, r.w, r.h, 4, TFT_GREEN);
        gfx.setTextDatum(MC_DATUM);
        gfx.setTextColor(TFT_GREEN, TFT_BLACK);
        gfx.drawString(label, r.x + r.w / 2, r.y + r.h / 2);
        gfx.setTextDatum(TL_DATUM);
    }

    void drawLegend(TFT_eSPI& gfx, int16_t y) {
        bool metric = LocationManager::useMetricUnits();

        char lowLabel[10], midLabel[10], highLabel[10];
        if (metric) {
            int lowM = (int)(Units::feetToMeters(Config::COLOR_LOW_ALT_THRESHOLD_FT) / 100) * 100;
            int midM = (int)(Units::feetToMeters(Config::COLOR_MID_ALT_THRESHOLD_FT) / 100) * 100;
            snprintf(lowLabel, sizeof(lowLabel), "<%dm", lowM);
            snprintf(midLabel, sizeof(midLabel), "%d-%dm", lowM, midM);
            snprintf(highLabel, sizeof(highLabel), ">%dm", midM);
        } else {
            snprintf(lowLabel, sizeof(lowLabel), "<10k ft");
            snprintf(midLabel, sizeof(midLabel), "10-30k");
            snprintf(highLabel, sizeof(highLabel), ">30k ft");
        }

// Use the same colorForAltitude() function as for the aircraft markers
        // themselves (with a typical altitude per band) - otherwise the
        // legend would show the BRIGHT colors during active night dimming (sunset to sunrise),
        // while the markers/labels on the radar are already dimmed.
        // This caused e.g. a red aircraft to appear dark orange at night,
        // even though the legend still showed pure red.
        struct { uint16_t color; const char* label; } items[3] = {
            {colorForAltitude(gfx, 0),                                   lowLabel},
            {colorForAltitude(gfx, Config::COLOR_LOW_ALT_THRESHOLD_FT),  midLabel},
            {colorForAltitude(gfx, Config::COLOR_MID_ALT_THRESHOLD_FT),  highLabel},
        };
        int16_t segW = Config::SCREEN_WIDTH / 3;
        gfx.setTextColor(TFT_WHITE, TFT_BLACK);

// Outer columns (green/red) stay at their fixed 1/3 grid
        // position (x0 = i*segW+6). The middle (yellow) column was
        // previously positioned just as rigidly, but visually sat too
        // far right: its label ("3000-9100") is noticeably longer than
        // the outer labels, leaving hardly any space on the right to the
        // red entry, while lots of empty space remained on the left next to the short green
        // label. Now the yellow column is instead placed
        // centered in the gap between the end of the green text and the start of the
        // red dot.
        int16_t x0Low = 0 * segW + 6;
        int16_t x0High = 2 * segW + 6;

        gfx.fillCircle(x0Low, y - 5, 3, items[0].color);
        gfx.setCursor(x0Low + 7, y);
        gfx.print(items[0].label);

        gfx.fillCircle(x0High, y - 5, 3, items[2].color);
        gfx.setCursor(x0High + 7, y);
        gfx.print(items[2].label);

        int16_t lowTextEndX = x0Low + 7 + gfx.textWidth(items[0].label);
        int16_t highDotStartX = x0High - 3;
        int16_t midBlockW = 10 + gfx.textWidth(items[1].label); // Punktdurchmesser (6) + 4px Abstand + Textbreite
        int16_t gap = highDotStartX - lowTextEndX;
        int16_t x0Mid = lowTextEndX + 3 + (gap > midBlockW ? (gap - midBlockW) / 2 : 0);

        gfx.fillCircle(x0Mid, y - 5, 3, items[1].color);
        gfx.setCursor(x0Mid + 7, y);
        gfx.print(items[1].label);

// Second legend row for the blue ground vehicle squares - only
        // when they are actually visible (Flight Options >
        // "Hide ground vehicles" == off). infoBarHeight() reserves
        // additional space for this only in that case, see
        // computeLayout().
        if (!SettingsStore::hideGroundVehicles()) {
            int16_t gy = (int16_t)(y + INFO_BAR_GROUND_ROW_H);
            gfx.fillRect(3, (int16_t)(gy - 8), 6, 6, colorForGroundVehicle(gfx));
            gfx.setCursor(13, gy);
            gfx.print(I18n::t(StringId::LEGEND_GROUND_VEHICLE));
        }
    }

    void drawWorldMap(TFT_eSPI& gfx, const Layout& L) {
        constexpr uint16_t dim = 0x0320;
        float scaleX = (2.0f * L.radius) / WorldMap::GRID_W;
        float scaleY = (2.0f * L.radius) / WorldMap::GRID_H;
        int32_t radiusSq = (int32_t)(L.radius - 2) * (L.radius - 2);

        for (uint8_t row = 0; row < WorldMap::GRID_H; row++) {
            uint64_t bits = WorldMap::ROWS[row];
            if (bits == 0) continue;
            for (uint8_t col = 0; col < WorldMap::GRID_W; col++) {
                if (!(bits & (1ULL << (WorldMap::GRID_W - 1 - col)))) continue;

                int16_t px = L.cx - L.radius + (int16_t)((col + 0.5f) * scaleX);
                int16_t py = L.cy - L.radius + (int16_t)((row + 0.5f) * scaleY);

                int16_t dx = px - L.cx;
                int16_t dy = py - L.cy;
                if ((int32_t)dx * dx + (int32_t)dy * dy > radiusSq) continue;

                gfx.drawPixel(px, py, dim);
            }
        }
    }

    void drawSweepLine(TFT_eSPI& gfx, const Layout& L, float angleDeg, uint16_t color) {
        double rad = angleDeg * DEG_TO_RAD;
        int16_t x2 = L.cx + (int16_t)(L.radius * sin(rad));
        int16_t y2 = L.cy - (int16_t)(L.radius * cos(rad));
        gfx.drawLine(L.cx, L.cy, x2, y2, color);
    }

    void drawStaticBackground(TFT_eSPI& gfx, const Layout& L, float rangeKm) {
        gfx.drawCircle(L.cx, L.cy, L.radius, TFT_DARKGREY);
        gfx.drawCircle(L.cx, L.cy, L.radius * 2 / 3, TFT_DARKGREY);
        gfx.drawCircle(L.cx, L.cy, L.radius / 3, TFT_DARKGREY);
        gfx.drawFastHLine(L.cx - L.radius, L.cy, L.radius * 2, TFT_DARKGREY);
        gfx.drawFastVLine(L.cx, L.cy - L.radius, L.radius * 2, TFT_DARKGREY);

        gfx.setTextColor(TFT_DARKGREY, TFT_BLACK);
        gfx.setTextDatum(MC_DATUM);
        gfx.drawString("N", L.cx, L.cy - L.radius - 8);
        gfx.drawString("S", L.cx, L.cy + L.radius - 10);
        gfx.drawString("E", L.cx + L.radius - 10, L.cy);
        gfx.drawString("W", L.cx - L.radius + 10, L.cy);
// Ring labels (intermediate distances) now respect the
        // unit setting (Menu > Units) - previously always in km,
        // even when Imperial (nm) was set. Same conversion
        // pattern as the range button below and the legend above.
        bool metric = LocationManager::useMetricUnits();
        float displayRange = metric ? rangeKm : Units::kmToNm(rangeKm);
        char ringLabel[8];
        snprintf(ringLabel, sizeof(ringLabel), "%.0f", displayRange / 3);
        gfx.drawString(ringLabel, L.cx, L.cy - L.radius / 3);
        snprintf(ringLabel, sizeof(ringLabel), "%.0f", displayRange * 2 / 3);
        gfx.drawString(ringLabel, L.cx, L.cy - L.radius * 2 / 3);
        gfx.setTextDatum(TL_DATUM);
    }

// Marquee state for ONE detail panel line - same basic
    // principle as InfoMarquee above, but the detail panel has up to
    // nine such lines simultaneously (airline, model, type, altitude,
    // speed, climb/sink rate, distance/bearing, squawk, seats),
    // hence a separate state per line instead of a single global
    // instance. y/h/maxWidth/fg remember the line geometry so that
    // tickDetailPanelMarquees() (see below) knows where/how to
    // redraw each line without extra parameters.
    struct LineMarquee {
        String text;
        String ring;
        bool needsScroll = false;
        int32_t charOffset = 0;
        uint32_t lastStepMs = 0;
        int16_t y = 0, h = 0, maxWidth = 0;
        uint16_t fg = TFT_GREEN;
    };

    struct PanelState {
        bool valid = false;
        char hex[7] = {0};
        String callsignText;
        LineMarquee airline, model, type, route, alt, speed, climb, distHeading, squawk, seats;
    };
    PanelState lastPanel;

// Redraws a detail panel line when its text has changed
    // (or the panel is being rebuilt) - remembers whether
    // the text is too wide for the available width
    // (needsScroll) and builds the ring buffer for the
    // marquee if needed (same pattern as infoMarqueeWindow() above).
    // Lines that are too wide ("Model: ...", "Distance: ...") are NO
    // LONGER abbreviated with "..." but scrolled horizontally - see
    // tickDetailPanelMarquees() below for the part that
    // actually advances the scrolling between data updates
    // (render() typically only supplies new values every ~300ms,
    // which would be far too rare for smooth scrolling).
    void updateMarqueeLine(TFT_eSPI& gfx, int16_t y, int16_t h, int16_t maxWidth,
                            uint16_t fg, LineMarquee& m, const String& newText, bool forceFull) {
// Always update geometry/color (even without text change) -
        // tickDetailPanelMarquees() needs these values to redraw
        // at the correct position on the next scroll step.
        m.y = y;
        m.h = h;
        m.maxWidth = maxWidth;
        m.fg = fg;

        if (!forceFull && m.text == newText) return;

        m.text = newText;
        m.needsScroll = gfx.textWidth(newText) > maxWidth;
        String withGap = newText + "   "; // 3 space gap before repetition
        m.ring = withGap + withGap;
        m.charOffset = 0;
        m.lastStepMs = millis();

        gfx.fillRect(0, y - 14, Config::SCREEN_WIDTH, h, TFT_BLACK);
        gfx.setTextColor(fg, TFT_BLACK);
        gfx.setCursor(8, y);
        gfx.print(m.needsScroll ? infoMarqueeWindow(gfx, m.ring, 0, maxWidth) : newText);
    }

// Advances a single detail panel line if it is too
    // wide (needsScroll) and enough time has passed since the last step
    // - otherwise nothing happens (no unnecessary redrawing
    // for lines that fit completely). Called by
    // tickDetailPanelMarquees() for all nine lines.
    void advanceAndDrawMarqueeLine(TFT_eSPI& gfx, LineMarquee& m) {
        if (!m.needsScroll) return;

        uint32_t now = millis();
        if (now - m.lastStepMs < INFO_MARQUEE_STEP_MS) return;
        m.lastStepMs = now;

        m.charOffset++;
        int32_t singleLen = (int32_t)m.text.length() + 3;
        if (m.charOffset >= singleLen) m.charOffset = 0;

        gfx.fillRect(0, m.y - 14, Config::SCREEN_WIDTH, m.h, TFT_BLACK);
        gfx.setTextColor(m.fg, TFT_BLACK);
        gfx.setCursor(8, m.y);
        gfx.print(infoMarqueeWindow(gfx, m.ring, m.charOffset, m.maxWidth));
    }

// Lets all detail panel lines scroll - while the panel
    // is open, tick() (every ~80ms) calls this, in BETWEEN much
    // more often than render() (which only fires on new aircraft data,
    // every ~300ms). Without this additional
    // call, a long line would jump one step on each render() call
    // but would not scroll smoothly.
    void tickDetailPanelMarquees(TFT_eSPI& gfx) {
        if (!lastPanel.valid) return;
        advanceAndDrawMarqueeLine(gfx, lastPanel.airline);
        advanceAndDrawMarqueeLine(gfx, lastPanel.model);
        advanceAndDrawMarqueeLine(gfx, lastPanel.type);
        advanceAndDrawMarqueeLine(gfx, lastPanel.route);
        advanceAndDrawMarqueeLine(gfx, lastPanel.alt);
        advanceAndDrawMarqueeLine(gfx, lastPanel.speed);
        advanceAndDrawMarqueeLine(gfx, lastPanel.climb);
        advanceAndDrawMarqueeLine(gfx, lastPanel.distHeading);
        advanceAndDrawMarqueeLine(gfx, lastPanel.squawk);
        advanceAndDrawMarqueeLine(gfx, lastPanel.seats);
    }

    void drawDetailPanel(TFT_eSPI& gfx, Aircraft& a) {
        AirlineLookup::resolve(a);
        AircraftDetails::Info details = AircraftDetails::get(a.hex);

        int16_t panelTop = Config::SCREEN_HEIGHT - DETAIL_PANEL_H;
        constexpr int16_t textMaxWidth = Config::SCREEN_WIDTH - 16;
        constexpr int16_t LINE_H = 22;

        bool forceFull = !lastPanel.valid || strcmp(lastPanel.hex, a.hex) != 0;
        if (forceFull) {
            gfx.fillRect(0, panelTop, Config::SCREEN_WIDTH, DETAIL_PANEL_H, TFT_BLACK);
            gfx.drawRect(0, panelTop, Config::SCREEN_WIDTH, DETAIL_PANEL_H, TFT_GREEN);
            lastPanel = PanelState{};
            strncpy(lastPanel.hex, a.hex, sizeof(lastPanel.hex) - 1);
        }

        int16_t y = panelTop + 26;

        {
            String txt = a.callsign[0] ? a.callsign : a.hex;
            if (forceFull || lastPanel.callsignText != txt) {
                gfx.fillRect(0, y - 22, Config::SCREEN_WIDTH, 28, TFT_BLACK);
                gfx.setTextColor(TFT_GREEN, TFT_BLACK);
                gfx.setTextSize(2);
                printLineTruncated(gfx, 8, y, textMaxWidth, txt);
                gfx.setTextSize(1);
                lastPanel.callsignText = txt;
            }
        }
        y += 30;

        updateMarqueeLine(gfx, y, LINE_H, textMaxWidth, TFT_GREEN, lastPanel.airline,
                   String(a.airlineName), forceFull);
        y += LINE_H;

        String modelLine = details.loading
            ? String(I18n::t(StringId::DETAIL_MODEL)) + I18n::t(StringId::DETAIL_LOADING_DOTS)
            : String(I18n::t(StringId::DETAIL_MODEL)) + (details.model[0] ? details.model : I18n::t(StringId::DETAIL_UNKNOWN));
        updateMarqueeLine(gfx, y, LINE_H, textMaxWidth, TFT_GREEN, lastPanel.model, modelLine, forceFull);
        y += LINE_H;

        String typeLine = String(I18n::t(StringId::DETAIL_TYPE)) + (a.typeCode[0] ? a.typeCode : I18n::t(StringId::DETAIL_UNKNOWN));
        updateMarqueeLine(gfx, y, LINE_H, textMaxWidth, TFT_GREEN, lastPanel.type, typeLine, forceFull);
        y += LINE_H;

// Origin/destination airport (ICAO code) via AircraftDetails::get() -
        // is queried together with the model (see aircraft_details.cpp),
        // but resolved via the callsign instead of the hex code. Without
        // a callsign (e.g. some VFR aircraft) the route remains
        // fundamentally unknown, no lookup needed.
        String routeLine;
        if (!a.callsign[0]) {
            routeLine = String(I18n::t(StringId::DETAIL_ROUTE)) + I18n::t(StringId::DETAIL_UNKNOWN);
        } else if (details.loading) {
            routeLine = String(I18n::t(StringId::DETAIL_ROUTE)) + I18n::t(StringId::DETAIL_LOADING_DOTS);
        } else if (details.routeOrigin[0] && details.routeDest[0]) {
            routeLine = String(I18n::t(StringId::DETAIL_ROUTE)) + details.routeOrigin + " -> " + details.routeDest;
        } else {
            routeLine = String(I18n::t(StringId::DETAIL_ROUTE)) + I18n::t(StringId::DETAIL_UNKNOWN);
        }
        updateMarqueeLine(gfx, y, LINE_H, textMaxWidth, TFT_GREEN, lastPanel.route, routeLine, forceFull);
        y += LINE_H;

        char buf[48];
        snprintf(buf, sizeof(buf), "%s%.0fm / %.0fft", I18n::t(StringId::DETAIL_ALT),
                 Units::feetToMeters((float)a.altBaroFt), (float)a.altBaroFt);
        updateMarqueeLine(gfx, y, LINE_H, textMaxWidth, TFT_GREEN, lastPanel.alt, String(buf), forceFull);
        y += LINE_H;

        snprintf(buf, sizeof(buf), "%s%.0fkm/h / %.0fkt", I18n::t(StringId::DETAIL_SPEED),
                 Units::ktToKmh(a.groundSpeedKt), a.groundSpeedKt);
        updateMarqueeLine(gfx, y, LINE_H, textMaxWidth, TFT_GREEN, lastPanel.speed, String(buf), forceFull);
        y += LINE_H;

        String climbLine;
        if (a.vertRateFtMin > 100) {
            snprintf(buf, sizeof(buf), "%s+%dft/min", I18n::t(StringId::DETAIL_CLIMB), a.vertRateFtMin);
            climbLine = buf;
        } else if (a.vertRateFtMin < -100) {
            snprintf(buf, sizeof(buf), "%s%dft/min", I18n::t(StringId::DETAIL_DESCENT), a.vertRateFtMin);
            climbLine = buf;
        } else {
            climbLine = I18n::t(StringId::DETAIL_LEVEL);
        }
        updateMarqueeLine(gfx, y, LINE_H, textMaxWidth, TFT_GREEN, lastPanel.climb, climbLine, forceFull);
        y += LINE_H;

// In addition to km/nm also miles (mi) - nm alone was
        // not self-explanatory for lay users from countries with
        // imperial units (especially the US), "miles" is the more common
        // everyday distance unit there (nm still remains since it matches
        // speed in kt: 1 kt = 1 nm/h).
        snprintf(buf, sizeof(buf), "%s%.0fkm / %.0fnm / %.0fmi  %s%.0f", I18n::t(StringId::DETAIL_DIST),
                 a.distanceKm, Units::kmToNm(a.distanceKm), Units::kmToMi(a.distanceKm),
                 I18n::t(StringId::DETAIL_HDG), a.headingDeg);
        updateMarqueeLine(gfx, y, LINE_H, textMaxWidth, TFT_GREEN, lastPanel.distHeading, String(buf), forceFull);
        y += LINE_H;

        String squawkLine = String(I18n::t(StringId::DETAIL_SQUAWK)) + (a.squawk[0] ? a.squawk : I18n::t(StringId::DETAIL_UNKNOWN));
        updateMarqueeLine(gfx, y, LINE_H, textMaxWidth, TFT_GREEN, lastPanel.squawk, squawkLine, forceFull);
        y += LINE_H;

        String seatsLine = a.estSeats > 0
            ? String(I18n::t(StringId::DETAIL_SEATS_EST)) + a.estSeats
            : String(I18n::t(StringId::DETAIL_SEATS_UNKNOWN));
        updateMarqueeLine(gfx, y, LINE_H, textMaxWidth, TFT_GREEN, lastPanel.seats, seatsLine, forceFull);
        y += 22;

        if (forceFull) {
            gfx.setTextColor(TFT_DARKGREEN, TFT_BLACK);
            gfx.setCursor(8, y);
            gfx.print(I18n::t(StringId::DETAIL_TAP_CLOSE));
        }

        lastPanel.valid = true;
    }

    constexpr uint8_t STAR_COUNT = 28;
    struct Star {
        int16_t x, y;
        uint8_t phase;
        uint8_t speed;
    };
    Star stars[STAR_COUNT];
    bool starsInitialized = false;

    void initStarsIfNeeded() {
        if (starsInitialized) return;
        int16_t panelTop = Config::SCREEN_HEIGHT - DETAIL_PANEL_H;
        randomSeed((uint32_t)esp_random());
        for (uint8_t i = 0; i < STAR_COUNT; i++) {
            stars[i].x = 6 + random(0, Config::SCREEN_WIDTH - 12);
            stars[i].y = panelTop + 10 + random(0, DETAIL_PANEL_H - 20);
            stars[i].phase = (uint8_t)random(0, 256);
            stars[i].speed = 1 + random(0, 3);
        }
        starsInitialized = true;
    }

    void updateDetailPanelStars(TFT_eSPI& gfx) {
        initStarsIfNeeded();
        for (uint8_t i = 0; i < STAR_COUNT; i++) {
            stars[i].phase += stars[i].speed;
            uint8_t bright = (stars[i].phase < 128)
                ? (uint8_t)(stars[i].phase * 2)
                : (uint8_t)((255 - stars[i].phase) * 2);
            uint16_t color = gfx.color565(0, bright, 0);
            gfx.drawPixel(stars[i].x, stars[i].y, color);
        }
    }

// Background stars OUTSIDE the radar circle (requested: the same
    // decorative star twinkling as in the detail panel/menu, but without
    // colliding with the constantly redrawn circle content - THAT would
    // cause stuttering, since the sweep line/blips/rings within the
    // circle are redrawn on every tick() anyway and would constantly
    // swallow the stars there). Outside the circle the background remains
    // permanently black and is touched by no one else - the stars can
    // freely twinkle there, completely independent of sweep line/blip
    // redraws.
    constexpr uint8_t BG_STAR_COUNT = 20;
    struct BgStar {
        int16_t x, y;
        uint8_t phase;
        uint8_t speed;
    };
    BgStar bgStars[BG_STAR_COUNT];
    bool bgStarsInitialized = false;

// Places each star via rejection sampling somewhere in the area
    // [top..L.infoTop) x [0..SCREEN_WIDTH), but only if the point
    // is outside radius+MARGIN around the circle center (MARGIN
    // additionally keeps distance from the ring and the "N" compass label
    // just outside the circle). If an attempt after 25 tries finds no
    // suitable point (practically never, since there is always plenty
    // of space left/right of the circle), the last attempted point is
    // simply used - purely cosmetic feature, no reason for an
    // infinite loop.
    void initBgStarsIfNeeded(const Layout& L, int16_t top) {
        if (bgStarsInitialized) return;
        randomSeed((uint32_t)esp_random());
        constexpr int16_t MARGIN = 6;
        int32_t minDist = L.radius + MARGIN;
        int32_t minDistSq = minDist * minDist;
        for (uint8_t i = 0; i < BG_STAR_COUNT; i++) {
            int16_t x = 0, y = 0;
            for (uint8_t attempt = 0; attempt < 25; attempt++) {
                x = (int16_t)random(2, Config::SCREEN_WIDTH - 2);
                y = (int16_t)random(top + 2, L.infoTop - 2);
                int32_t dx = x - L.cx, dy = y - L.cy;
                if (dx * dx + dy * dy > minDistSq) break;
            }
            bgStars[i].x = x;
            bgStars[i].y = y;
            bgStars[i].phase = (uint8_t)random(0, 256);
            bgStars[i].speed = (uint8_t)(1 + random(0, 3));
        }
        bgStarsInitialized = true;
    }

    void updateBgStars(TFT_eSPI& gfx, const Layout& L, int16_t top) {
        initBgStarsIfNeeded(L, top);
        for (uint8_t i = 0; i < BG_STAR_COUNT; i++) {
            bgStars[i].phase += bgStars[i].speed;
            uint8_t bright = (bgStars[i].phase < 128)
                ? (uint8_t)(bgStars[i].phase * 2)
                : (uint8_t)((255 - bgStars[i].phase) * 2);
            uint16_t color = gfx.color565(0, bright, 0);
            gfx.drawPixel(bgStars[i].x, bgStars[i].y, color);
        }
    }
}

void render(TFT_eSPI& tft, int16_t top) {
    Layout L = computeLayout(top);
    float rangeKm = Config::RANGE_STEPS_KM[SettingsStore::rangeIndex()];

    bool panelAlreadyOpen = selectedHex[0] && lastPanel.valid &&
                            strcmp(lastPanel.hex, selectedHex) == 0;

    if (panelAlreadyOpen) {
        AircraftTable::lock();
        Aircraft* table = AircraftTable::raw();
        Aircraft selected{};
        bool found = false;
        for (uint8_t i = 0; i < AircraftTable::capacity(); i++) {
            if (table[i].valid && strcmp(table[i].hex, selectedHex) == 0) {
                selected = table[i];
                found = true;
                break;
            }
        }
        AircraftTable::unlock();

        if (found && selected.distanceKm <= rangeKm * 1.05f) {
            tft.startWrite();
            drawDetailPanel(tft, selected);
            tft.endWrite();
            return;
        }
        selectedHex[0] = 0;
        lastPanel.valid = false;
    }

    tft.startWrite();

    tft.fillRect(0, top, Config::SCREEN_WIDTH, Config::SCREEN_HEIGHT - top, TFT_BLACK);

    drawWorldMap(tft, L);
    drawStaticBackground(tft, L, rangeKm);

    drawSweepLine(tft, L, sweepAngleDeg, sweepLineColor(tft));
    prevSweepAngleDeg = sweepAngleDeg;

    tft.fillCircle(L.cx, L.cy, 3, TFT_WHITE);

    static Aircraft snapshot[Config::MAX_TRACKED_AIRCRAFT];
    uint8_t count = 0;

    AircraftTable::lock();
    Aircraft* table = AircraftTable::raw();
    for (uint8_t i = 0; i < AircraftTable::capacity(); i++) {
        if (table[i].valid) snapshot[count++] = table[i];
    }
    AircraftTable::unlock();

    bool selectionStillPresent = false;
    Aircraft selected{};
    uint8_t visibleCount = 0; // after all filters (range, ground vehicles, airline filter)

    for (uint8_t i = 0; i < MAX_HIT_POINTS; i++) hitPoints[i].valid = false;

    for (uint8_t i = 0; i < count && i < MAX_HIT_POINTS; i++) {
        Aircraft& a = snapshot[i];
        if (a.distanceKm > rangeKm * 1.05f) continue;

        if (SettingsStore::hideGroundVehicles() && (a.category[0] == 'C' || a.onGround)) continue;

if (AirlineFilter::isHidden(a.callsign)) continue;

        uint8_t altMode = SettingsStore::altFilterIndex();
        if (altMode == 1 && a.altBaroFt >= (int32_t)Config::COLOR_LOW_ALT_THRESHOLD_FT) continue;
        if (altMode == 2 && a.altBaroFt < (int32_t)Config::COLOR_LOW_ALT_THRESHOLD_FT) continue;

        visibleCount++;

        RadarMath::PolarCoord polar{a.distanceKm, a.bearingDeg};
        RadarMath::ScreenPoint pt = RadarMath::toScreen(polar, L.cx, L.cy, L.radius, rangeKm);

// ADS-B emitter category "C*" = ground vehicle (only ever
        // visible if "Hide ground vehicles" is off, see filter
        // above) - separate color/marker instead of altitude-based
        // rendering, see drawGroundVehicleMarker()/colorForGroundVehicle().
        bool isGroundVehicle = a.category[0] == 'C';
        bool isRotorcraft = a.category[0] == 'A' && a.category[1] == '7';
// ADS-B emitter category "A5" = "Heavy" - separate marker shape (see
        // drawHeavyMarker()), independent of any ring marking.
        bool isHeavy = a.category[0] == 'A' && a.category[1] == '5';
        uint16_t color = isGroundVehicle ? colorForGroundVehicle(tft) : colorForAltitude(tft, a.altBaroFt);
        bool isSelected = selectedHex[0] && strcmp(a.hex, selectedHex) == 0;
        bool isEmergency = SettingsStore::emergencyAlertEnabled() && isEmergencySquawk(a.squawk);
        bool isWatched = SettingsStore::watchlistAlertEnabled() && AircraftWatchlist::isWatched(a.callsign);

        if (isSelected) {
            tft.drawCircle(pt.x, pt.y, 9, TFT_WHITE);
            selectionStillPresent = true;
            selected = a;
            drawBearingIndicator(tft, L, a.bearingDeg);
        }
        if (isGroundVehicle) {
            drawGroundVehicleMarker(tft, pt.x, pt.y, color);
        } else if (isRotorcraft) {
            drawHelicopterMarker(tft, pt.x, pt.y, color);
        } else if (isHeavy) {
            drawHeavyMarker(tft, pt.x, pt.y, a.headingDeg, color);
        } else {
            drawAircraftMarker(tft, pt.x, pt.y, a.headingDeg, color);
        }

        if (isEmergency) {
            tft.drawCircle(pt.x, pt.y, 12, TFT_RED);
        } else if (isWatched) {
            tft.drawCircle(pt.x, pt.y, 12, TFT_CYAN);
        }

        tft.setTextColor(color);
        tft.setTextDatum(BC_DATUM);
        const char* label = a.callsign[0] ? a.callsign : a.hex;
        tft.drawString(label, pt.x, pt.y - 8);
        tft.setTextDatum(TL_DATUM);

        hitPoints[i].x = pt.x;
        hitPoints[i].y = pt.y;
        hitPoints[i].valid = true;
        hitPoints[i].color = color;
        hitPoints[i].headingDeg = a.headingDeg;
        hitPoints[i].distanceKm = a.distanceKm;
        hitPoints[i].isEmergency = isEmergency;
        hitPoints[i].isWatched = isWatched;
        hitPoints[i].isGroundVehicle = isGroundVehicle;
        hitPoints[i].isRotorcraft = isRotorcraft;
        hitPoints[i].isHeavy = isHeavy;
        strncpy(hitPoints[i].hex, a.hex, sizeof(hitPoints[i].hex) - 1);
        strncpy(hitPoints[i].callsign, a.callsign, sizeof(hitPoints[i].callsign) - 1);
    }

    if (visibleCount > 0) lastAircraftSeenMs = millis();

    if (selectedHex[0] && !selectionStillPresent) {
        selectedHex[0] = 0;
    }

    if (selectionStillPresent) {
        tft.endWrite();
        drawDetailPanel(tft, selected);
        tft.startWrite();
    } else {
lastPanel.valid = false;
        int16_t infoTop = L.infoTop;
        tft.drawFastHLine(0, infoTop, Config::SCREEN_WIDTH, TFT_DARKGREY);
        // Info bar button row: [?] [S] [L] [50km]
        char rangeLabel[8];
        bool rangeMetric = LocationManager::useMetricUnits();
if (rangeMetric) {
            snprintf(rangeLabel, sizeof(rangeLabel), "%.0fkm", rangeKm);
        } else {
            snprintf(rangeLabel, sizeof(rangeLabel), "%.0fnm", Units::kmToNm(rangeKm));
        }
        uint8_t altIdx = SettingsStore::altFilterIndex();
        const char* altLabels[] = {"All", "<10k", ">10k"};
        drawButton(tft, L.helpBtn, "?");
        drawButton(tft, L.searchBtn, "S");
        drawButton(tft, L.listBtn, "L");
        drawButton(tft, L.altBtn, altLabels[altIdx]);
        drawButton(tft, L.rangeBtn, rangeLabel);

        drawLegend(tft, infoTop + 44);
    }

    tft.endWrite();
}

void tick(TFT_eSPI& tft, int16_t top, uint32_t deltaMs) {
    if (selectedHex[0]) {
        tft.startWrite();
        updateDetailPanelStars(tft);
// Lets overly wide detail panel lines (e.g. "Model: ..." or
        // "Distance: ...") scroll, instead of being statically truncated
        // with "..." - render() only supplies new values every
        // ~300ms, which is not enough for smooth scrolling,
        // so it is additionally advanced here in the 80ms tick.
        tickDetailPanelMarquees(tft);
        tft.endWrite();
        return;
    }

    Layout L = computeLayout(top);
    float rangeKm = Config::RANGE_STEPS_KM[SettingsStore::rangeIndex()];

    tft.startWrite();

// Twinkling outside the radar circle - runs at the same 80ms rate as
    // the sweep line so it looks smooth. render() (on every aircraft
    // update, every ~300ms) clears the entire content area with fillRect
    // and redraws it WITHOUT re-setting the stars - this is
    // intentional (just like the detail panel star field): the next
    // tick() round (at most 80ms later) will simply make them
    // twinkle again, which is too brief to be perceived as stuttering.
    updateBgStars(tft, L, top);

    if (prevSweepAngleDeg >= 0.0f) {
        drawSweepLine(tft, L, prevSweepAngleDeg, TFT_BLACK);
        drawStaticBackground(tft, L, rangeKm);
        tft.fillCircle(L.cx, L.cy, 3, TFT_WHITE);
    }

    sweepAngleDeg += SWEEP_DEGREES_PER_SEC * (deltaMs / 1000.0f);
    if (sweepAngleDeg >= 360.0f) sweepAngleDeg -= 360.0f;

    drawSweepLine(tft, L, sweepAngleDeg, sweepLineColor(tft));
    prevSweepAngleDeg = sweepAngleDeg;

    for (uint8_t i = 0; i < MAX_HIT_POINTS; i++) {
        if (!hitPoints[i].valid) continue;
        const HitPoint& hp = hitPoints[i];

        bool inAlertRange = hp.distanceKm <= Config::LED_ALERT_RADIUS_KM;
        if (inAlertRange && !ledBlinkOn) {
// Blink-off phase: previously a blanket 40x30px
            // black rectangle was drawn to "hide" the marker -
            // but that also covered the radar rings/compass lines
            // underneath (equally for all altitude colors, since this
            // blink logic is purely distance-based). Instead, exactly
            // the same shapes that are drawn during normal rendering
            // below (marker, emergency/watchlist ring, label) are
            // now drawn in black - this makes them pixel-perfectly
            // invisible again without touching anything outside
            // those shapes.
            if (hp.isGroundVehicle) {
                drawGroundVehicleMarker(tft, hp.x, hp.y, TFT_BLACK);
            } else if (hp.isRotorcraft) {
                drawHelicopterMarker(tft, hp.x, hp.y, TFT_BLACK);
            } else if (hp.isHeavy) {
                drawHeavyMarker(tft, hp.x, hp.y, hp.headingDeg, TFT_BLACK);
            } else {
                drawAircraftMarker(tft, hp.x, hp.y, hp.headingDeg, TFT_BLACK);
            }
            if (hp.isEmergency || hp.isWatched) {
                tft.drawCircle(hp.x, hp.y, 12, TFT_BLACK);
            }
            tft.setTextColor(TFT_BLACK);
            tft.setTextDatum(BC_DATUM);
            const char* blinkLabel = hp.callsign[0] ? hp.callsign : hp.hex;
            tft.drawString(blinkLabel, hp.x, hp.y - 8);
            tft.setTextDatum(TL_DATUM);
            continue;
        }

        if (hp.isGroundVehicle) {
            drawGroundVehicleMarker(tft, hp.x, hp.y, hp.color);
        } else if (hp.isRotorcraft) {
            drawHelicopterMarker(tft, hp.x, hp.y, hp.color);
        } else if (hp.isHeavy) {
            drawHeavyMarker(tft, hp.x, hp.y, hp.headingDeg, hp.color);
        } else {
            drawAircraftMarker(tft, hp.x, hp.y, hp.headingDeg, hp.color);
        }

        if (hp.isEmergency) {
            tft.drawCircle(hp.x, hp.y, 12, TFT_RED);
        } else if (hp.isWatched) {
            tft.drawCircle(hp.x, hp.y, 12, TFT_CYAN);
        }

        tft.setTextColor(hp.color);
        tft.setTextDatum(BC_DATUM);
        const char* label = hp.callsign[0] ? hp.callsign : hp.hex;
        tft.drawString(label, hp.x, hp.y - 8);
        tft.setTextDatum(TL_DATUM);
    }

// Info line at bottom (tap hint or "Empty Sky" timer) as
// continuous update of the last sighting for the "Empty Sky"
    // counter.
    uint8_t visibleCountNow = 0;
    for (uint8_t i = 0; i < MAX_HIT_POINTS; i++) {
        if (hitPoints[i].valid) visibleCountNow++;
    }
    if (visibleCountNow > 0) lastAircraftSeenMs = millis();

    tft.endWrite();
}

bool handleTap(TFT_eSPI& tft, int16_t x, int16_t y, int16_t top) {
    Layout L = computeLayout(top);

    if (selectedHex[0]) {
        for (uint8_t i = 0; i < MAX_HIT_POINTS; i++) {
            if (!hitPoints[i].valid) continue;
            int16_t dx = x - hitPoints[i].x;
            int16_t dy = y - hitPoints[i].y;
            if (dx * dx + dy * dy <= 12 * 12) {
                strncpy(selectedHex, hitPoints[i].hex, sizeof(selectedHex) - 1);
                AircraftDetails::request(hitPoints[i].hex, hitPoints[i].callsign);
                return true;
            }
        }
        selectedHex[0] = 0;
        lastPanel.valid = false;
        return true;
    }

    if (L.helpBtn.contains(x, y)) {
        runHelp(tft, top);
        return true;
    }

    if (L.searchBtn.contains(x, y)) {
        runSearch(tft, top);
        return true;
    }

if (L.listBtn.contains(x, y)) {
        bool hadSelection = runTable(tft, top);
        return true;
    }

    if (L.altBtn.contains(x, y)) {
        uint8_t idx = (SettingsStore::altFilterIndex() + 1) % Config::ALT_FILTER_COUNT;
        SettingsStore::setAltFilterIndex(idx);
        return true;
    }

    if (L.rangeBtn.contains(x, y)) {
        uint8_t idx = (SettingsStore::rangeIndex() + 1) % Config::RANGE_STEP_COUNT;
        SettingsStore::setRangeIndex(idx);
        return true;
    }

    for (uint8_t i = 0; i < MAX_HIT_POINTS; i++) {
        if (!hitPoints[i].valid) continue;
        int16_t dx = x - hitPoints[i].x;
        int16_t dy = y - hitPoints[i].y;
        if (dx * dx + dy * dy <= 12 * 12) {
            strncpy(selectedHex, hitPoints[i].hex, sizeof(selectedHex) - 1);
            AircraftDetails::request(hitPoints[i].hex, hitPoints[i].callsign);
            return true;
        }
    }

    uint32_t nowMs = millis();
    bool isDoubleTap = (nowMs - lastEmptyTapMs <= DOUBLE_TAP_MS) &&
                       (abs((int)x - (int)lastEmptyTapX) <= DOUBLE_TAP_RADIUS) &&
                       (abs((int)y - (int)lastEmptyTapY) <= DOUBLE_TAP_RADIUS);
    lastEmptyTapMs = nowMs;
    lastEmptyTapX = x;
    lastEmptyTapY = y;

    if (isDoubleTap) {
        uint8_t idx = SettingsStore::rangeIndex();
        idx = (idx == 0) ? (Config::RANGE_STEP_COUNT - 1) : (idx - 1);
        SettingsStore::setRangeIndex(idx);
        lastEmptyTapMs = 0;
    }

return true;
}

bool runTable(TFT_eSPI& tft, int16_t top) {
    constexpr int16_t ROW_H = 22;
    constexpr int16_t ROW_GAP = 3;
    constexpr int16_t PADDING = 6;
    constexpr int16_t TABLE_LEFT = PADDING;
    constexpr int16_t TABLE_RIGHT = Config::SCREEN_WIDTH - PADDING;
    constexpr int16_t TABLE_W = TABLE_RIGHT - TABLE_LEFT;
    int16_t TABLE_TOP = top + 4;
    constexpr int16_t NAV_H = 24;
    constexpr int16_t BTN_H = 30;
    constexpr int16_t BTN_Y = Config::SCREEN_HEIGHT - BTN_H - 4;
    constexpr int16_t NAV_Y = BTN_Y - ROW_H - ROW_GAP - 2;

    int16_t tableBottom = NAV_Y - 4;
    uint8_t rowsVisible = (tableBottom - TABLE_TOP) / (ROW_H + ROW_GAP);
    if (rowsVisible < 1) rowsVisible = 1;

    uint8_t scrollTop = 0;
    bool done = false;
    bool selected = false;
    MenuStars::reset();

    while (!done && !selected) {
        static Aircraft snapshot[Config::MAX_TRACKED_AIRCRAFT];
        uint8_t count = 0;
        float rangeKm = Config::RANGE_STEPS_KM[SettingsStore::rangeIndex()];

        AircraftTable::lock();
        Aircraft* table = AircraftTable::raw();
        for (uint8_t i = 0; i < AircraftTable::capacity(); i++) {
            if (!table[i].valid) continue;
            if (table[i].distanceKm > rangeKm * 1.05f) continue;
            if (SettingsStore::hideGroundVehicles() && (table[i].category[0] == 'C' || table[i].onGround)) continue;
if (AirlineFilter::isHidden(table[i].callsign)) continue;

            uint8_t altMode = SettingsStore::altFilterIndex();
            if (altMode == 1 && table[i].altBaroFt >= (int32_t)Config::COLOR_LOW_ALT_THRESHOLD_FT) continue;
            if (altMode == 2 && table[i].altBaroFt < (int32_t)Config::COLOR_LOW_ALT_THRESHOLD_FT) continue;

            snapshot[count++] = table[i];
        }
        AircraftTable::unlock();

        std::sort(snapshot, snapshot + count, [](const Aircraft& a, const Aircraft& b) {
            return a.distanceKm < b.distanceKm;
        });

        if (scrollTop > 0 && scrollTop + rowsVisible > count) {
            scrollTop = (count > rowsVisible) ? (uint8_t)(count - rowsVisible) : 0;
        }

        tft.fillRect(TABLE_LEFT, TABLE_TOP, TABLE_W, tableBottom - TABLE_TOP, TFT_BLACK);

        bool metric = LocationManager::useMetricUnits();
        int16_t y = TABLE_TOP;
        uint8_t drawn = 0;

        for (uint8_t i = scrollTop; i < count && drawn < rowsVisible; i++) {
            Aircraft& a = snapshot[i];
            Rect r = {TABLE_LEFT, y, TABLE_W, ROW_H};

            bool emergency = isEmergencySquawk(a.squawk);
            bool watched = AircraftWatchlist::isWatched(a.callsign);
            uint16_t borderColor = emergency ? TFT_RED : (watched ? TFT_CYAN : TFT_GREEN);
            tft.drawRoundRect(r.x, r.y, r.w, r.h, 3, borderColor);

            int16_t midY = r.y + r.h / 2;

            const char* label = a.callsign[0] ? a.callsign : a.hex;
            tft.setTextColor(TFT_GREEN, TFT_BLACK);
            tft.setTextDatum(ML_DATUM);
            tft.drawString(label, r.x + 4, midY);

            char buf[16];
            if (metric) {
                snprintf(buf, sizeof(buf), "%.0fm", Units::feetToMeters((float)a.altBaroFt));
            } else {
                snprintf(buf, sizeof(buf), "%.0fft", (float)a.altBaroFt);
            }
            tft.setTextColor(colorForAltitude(tft, a.altBaroFt), TFT_BLACK);
            tft.setTextDatum(MC_DATUM);
            tft.drawString(buf, r.x + r.w / 2, midY);

            if (metric) {
                snprintf(buf, sizeof(buf), "%.1fkm", a.distanceKm);
            } else {
                snprintf(buf, sizeof(buf), "%.1fnm", Units::kmToNm(a.distanceKm));
            }
            tft.setTextColor(TFT_GREEN, TFT_BLACK);
            tft.setTextDatum(MR_DATUM);
            tft.drawString(buf, r.x + r.w - 4, midY);

            tft.setTextDatum(TL_DATUM);

            y += ROW_H + ROW_GAP;
            drawn++;
        }

        if (count == 0) {
            tft.setTextColor(TFT_DARKGREY, TFT_BLACK);
            tft.setTextDatum(MC_DATUM);
            tft.drawString(I18n::t(StringId::AIRCRAFT_LIST_EMPTY),
                          Config::SCREEN_WIDTH / 2, (int16_t)(TABLE_TOP + ROW_H + 10));
            tft.setTextDatum(TL_DATUM);
        }

        bool canUp = scrollTop > 0;
        bool canDown = (uint16_t)(scrollTop + rowsVisible) < count;

        tft.fillRect(0, NAV_Y, Config::SCREEN_WIDTH, Config::SCREEN_HEIGHT - NAV_Y, TFT_BLACK);

        Rect upBtn     = {TABLE_LEFT, NAV_Y, 44, NAV_H};
        Rect downBtn   = {(int16_t)(TABLE_LEFT + 48), NAV_Y, 44, NAV_H};
        Rect radarBtn  = {(int16_t)(TABLE_LEFT + 100), NAV_Y, (int16_t)(TABLE_W - 100), NAV_H};

        drawButton(tft, upBtn, "^");
        drawButton(tft, downBtn, "v");
        drawButton(tft, radarBtn, I18n::t(StringId::BACK));

        TouchInput::Point tap;
        while (true) {
            if (TouchInput::wasTapped(tap)) break;
            MenuStars::update(tft);
            delay(20);
        }

        if (canUp && upBtn.contains(tap.x, tap.y)) {
            scrollTop--;
        } else if (canDown && downBtn.contains(tap.x, tap.y)) {
            scrollTop++;
        } else if (radarBtn.contains(tap.x, tap.y)) {
            done = true;
        } else {
            y = TABLE_TOP;
            for (uint8_t i = scrollTop; i < count; i++) {
                uint8_t idx = (uint8_t)(i - scrollTop);
                if (idx >= rowsVisible) break;
                Rect r = {TABLE_LEFT, y, TABLE_W, ROW_H};
                if (r.contains(tap.x, tap.y)) {
                    selectAircraft(snapshot[i].hex, snapshot[i].callsign);
                    selected = true;
                    break;
                }
                y += ROW_H + ROW_GAP;
            }
        }
    }

    // Wait briefly to let the tap release propagate before render() runs
    delay(50);
    return selected;
}

void runSearch(TFT_eSPI& tft, int16_t top) {
    MenuStars::reset();
    constexpr const char* ROW1 = "QWERTYUIOP";
    constexpr const char* ROW2 = "ASDFGHJKL";
    constexpr const char* ROW3 = "ZXCVBNM";
    constexpr const char* ROW4 = "0123456789";

    char buf[9] = {0};
    uint8_t len = 0;
    constexpr uint8_t MAX_LEN = 8;
    constexpr int16_t KEY_H = 32;
    constexpr int16_t KEY_GAP = 3;
    constexpr int16_t ROW0_Y = 64;

    auto layoutRow = [&](const char* row, int16_t y, Rect* outRects, uint8_t n) {
        int16_t usableW = Config::SCREEN_WIDTH - 8;
        int16_t keyW = (usableW - (n - 1) * KEY_GAP) / n;
        int16_t x = 4;
        for (uint8_t i = 0; i < n; i++) {
            outRects[i] = {x, y, keyW, KEY_H};
            x += keyW + KEY_GAP;
        }
    };

    Rect row1Rects[10], row2Rects[9], row3Rects[7], row4Rects[10];
    layoutRow(ROW1, ROW0_Y, row1Rects, 10);
    layoutRow(ROW2, ROW0_Y + KEY_H + KEY_GAP, row2Rects, 9);
    layoutRow(ROW3, ROW0_Y + 2 * (KEY_H + KEY_GAP), row3Rects, 7);
    layoutRow(ROW4, ROW0_Y + 3 * (KEY_H + KEY_GAP), row4Rects, 10);

    int16_t actionY = ROW0_Y + 4 * (KEY_H + KEY_GAP);
    Rect backspaceBtn = {4, actionY, 60, KEY_H};
    Rect cancelBtn    = {(int16_t)(Config::SCREEN_WIDTH / 2 - 48), actionY, 96, KEY_H};
    Rect searchBtn    = {(int16_t)(Config::SCREEN_WIDTH - 4 - 60), actionY, 60, KEY_H};

    uint32_t notFoundUntil = 0;
    bool showingNotFound = false;

    auto redraw = [&]() {
        tft.fillScreen(TFT_BLACK);
        tft.setTextColor(TFT_GREEN, TFT_BLACK);
tft.fillRect(8, 30, Config::SCREEN_WIDTH - 16, 28, TFT_BLACK);
        tft.drawRect(8, 30, Config::SCREEN_WIDTH - 16, 28, TFT_GREEN);
        tft.setTextSize(2);
        tft.setCursor(14, 52);
        if (buf[0] == 0) {
            tft.setTextColor(TFT_DARKGREY, TFT_BLACK);
            tft.setTextSize(1);
            tft.setCursor(14, 49);
            tft.print("Flight number or hex code");
            tft.setTextSize(2);
        } else {
            tft.setTextColor(TFT_GREEN, TFT_BLACK);
            tft.print(buf);
        }
        tft.setTextSize(1);

        if (showingNotFound) {
            tft.setTextColor(TFT_RED, TFT_BLACK);
            tft.setTextDatum(MC_DATUM);
            tft.drawString("Not found", Config::SCREEN_WIDTH / 2, actionY + KEY_H + 14);
            tft.setTextDatum(TL_DATUM);
        }

        for (uint8_t i = 0; i < 10; i++) drawButton(tft, row1Rects[i], String(ROW1[i]));
        for (uint8_t i = 0; i < 9; i++) drawButton(tft, row2Rects[i], String(ROW2[i]));
        for (uint8_t i = 0; i < 7; i++) drawButton(tft, row3Rects[i], String(ROW3[i]));
        for (uint8_t i = 0; i < 10; i++) drawButton(tft, row4Rects[i], String(ROW4[i]));
        drawButton(tft, backspaceBtn, "<-");
        drawButton(tft, cancelBtn, I18n::t(StringId::CANCEL));
        drawButton(tft, searchBtn, I18n::t(StringId::OK));
    };

    redraw();

    while (true) {
        if (showingNotFound && millis() >= notFoundUntil) {
            showingNotFound = false;
            redraw();
        }

        TouchInput::Point tap;
        if (!TouchInput::wasTapped(tap)) {
            MenuStars::update(tft);
            delay(20);
            continue;
        }

        if (showingNotFound) {
            showingNotFound = false;
            redraw();
            continue;
        }

        bool handled = false;

        for (uint8_t i = 0; i < 10 && !handled; i++) {
            if (row1Rects[i].contains(tap.x, tap.y) && len < MAX_LEN) { buf[len++] = ROW1[i]; handled = true; }
        }
        for (uint8_t i = 0; i < 9 && !handled; i++) {
            if (row2Rects[i].contains(tap.x, tap.y) && len < MAX_LEN) { buf[len++] = ROW2[i]; handled = true; }
        }
        for (uint8_t i = 0; i < 7 && !handled; i++) {
            if (row3Rects[i].contains(tap.x, tap.y) && len < MAX_LEN) { buf[len++] = ROW3[i]; handled = true; }
        }
        for (uint8_t i = 0; i < 10 && !handled; i++) {
            if (row4Rects[i].contains(tap.x, tap.y) && len < MAX_LEN) { buf[len++] = ROW4[i]; handled = true; }
        }

        if (!handled && backspaceBtn.contains(tap.x, tap.y)) {
            if (len > 0) { len--; buf[len] = 0; }
            handled = true;
        }
        if (!handled && cancelBtn.contains(tap.x, tap.y)) {
            return;
        }
        if (!handled && searchBtn.contains(tap.x, tap.y) && len > 0) {
            auto prefixMatch = [&](const char* str) -> bool {
                for (uint8_t j = 0; j < len; j++) {
                    if (str[j] == 0) return false;
                    char a = str[j], b = buf[j];
                    if (a >= 'a' && a <= 'z') a -= 32;
                    if (b >= 'a' && b <= 'z') b -= 32;
                    if (a != b) return false;
                }
                return true;
            };

            int bestIdx = -1;
            float bestDist = 1e9f;

            AircraftTable::lock();
            Aircraft* table = AircraftTable::raw();
            for (uint8_t i = 0; i < AircraftTable::capacity(); i++) {
                if (!table[i].valid) continue;
                if (!prefixMatch(table[i].callsign) && !prefixMatch(table[i].hex)) continue;
                if (table[i].distanceKm < bestDist) {
                    bestDist = table[i].distanceKm;
                    bestIdx = i;
                }
            }

            char mHex[7] = {0}, mCall[9] = {0};
            if (bestIdx >= 0) {
                strncpy(mHex, table[bestIdx].hex, sizeof(mHex) - 1);
                strncpy(mCall, table[bestIdx].callsign, sizeof(mCall) - 1);
            }
            AircraftTable::unlock();

            if (bestIdx >= 0) {
                selectAircraft(mHex, mCall);
                return;
            } else {
                showingNotFound = true;
                notFoundUntil = millis() + 1500;
                redraw();
                continue;
            }
        }

        if (handled) redraw();
    }
}

void runHelp(TFT_eSPI& tft, int16_t top) {
    tft.fillScreen(TFT_BLACK);

    constexpr int16_t X = 10;
    constexpr int16_t W = Config::SCREEN_WIDTH - 20;
    constexpr int16_t LBL_H = 14;
    int16_t y = 14;

    tft.setTextColor(TFT_GREEN, TFT_BLACK);
    tft.setTextSize(1);
    tft.setCursor(X, y);
    tft.print("Usage Guide");
    y += 24;

    auto line = [&](const char* text) {
        tft.setCursor(X, y);
        tft.print(text);
        y += LBL_H;
    };

    tft.setTextColor(TFT_WHITE, TFT_BLACK);
    line("Tap a plane on the radar to see");
    line("its details (model, altitude,");
    line("speed, route, squawk).");
    y += 4;

    tft.setTextColor(TFT_GREEN, TFT_BLACK);
    line("[?]  This help screen.");
    line("[S]  Search by flight number or");
    line("     hex code.");
    line("[L]  List all planes by distance.");
    line("[km] Cycle radar range: 10, 25,");
    line("     50, 100 km.");
    y += 4;

    tft.setTextColor(TFT_GREEN, TFT_BLACK);
    line("Altitude colors:");
    tft.setTextColor(TFT_GREEN, TFT_BLACK);
    line("  <10k ft         ");
    tft.setTextColor(TFT_YELLOW, TFT_BLACK);
    line("  10k - 30k ft    ");
    tft.setTextColor(TFT_RED, TFT_BLACK);
    line("  >30k ft         ");
    y += 4;

    tft.setTextColor(TFT_WHITE, TFT_BLACK);
    line("Menu > settings, WLAN, flight");
    line("options, watchlist & more.");

    Rect okBtn = {(int16_t)((Config::SCREEN_WIDTH - 120) / 2), (int16_t)(Config::SCREEN_HEIGHT - 50), 120, 36};
    drawButton(tft, okBtn, I18n::t(StringId::OK));

    MenuStars::reset();
    while (true) {
        TouchInput::Point tap;
        if (TouchInput::wasTapped(tap)) {
            if (okBtn.contains(tap.x, tap.y)) break;
            break; // any tap dismisses
        }
        MenuStars::update(tft);
        delay(20);
    }
}

void selectAircraft(const char* hex, const char* callsign) {
    strncpy(selectedHex, hex, sizeof(selectedHex) - 1);
    AircraftDetails::request(hex, callsign);
// Forces a complete rebuild of the detail panel on the next
    // render() - important if the screen was overwritten by another
    // screen (e.g. the aircraft list), otherwise unchanged lines would
    // be incorrectly skipped as "already there".
    lastPanel.valid = false;
}

void updateProximityAlert(uint32_t nowMs) {
    bool anyClose = false;
    bool anyEmergency = false;
    bool anyWatched = false;

    bool proximityOn = SettingsStore::proximityAlertEnabled();
    bool emergencyOn = SettingsStore::emergencyAlertEnabled();
    bool watchlistOn = SettingsStore::watchlistAlertEnabled();

    if (proximityOn || emergencyOn || watchlistOn) {
        AircraftTable::lock();
        Aircraft* table = AircraftTable::raw();
        for (uint8_t i = 0; i < AircraftTable::capacity(); i++) {
            if (!table[i].valid) continue;
            if (proximityOn && table[i].distanceKm <= Config::LED_ALERT_RADIUS_KM) anyClose = true;
            if (emergencyOn && isEmergencySquawk(table[i].squawk)) anyEmergency = true;
            if (watchlistOn && AircraftWatchlist::isWatched(table[i].callsign)) anyWatched = true;
        }
        AircraftTable::unlock();
    }

    LedAlert::Mode mode = anyEmergency ? LedAlert::Mode::EmergencyRed
                         : anyWatched  ? LedAlert::Mode::WatchlistBlue
                         : anyClose    ? LedAlert::Mode::ProximityGreen
                                       : LedAlert::Mode::Off;

    ledBlinkOn = LedAlert::update(mode, nowMs);
}

EmergencyInfo checkEmergency() {
    EmergencyInfo info;
    if (!SettingsStore::emergencyAlertEnabled()) return info;

    AircraftTable::lock();
    Aircraft* table = AircraftTable::raw();
    for (uint8_t i = 0; i < AircraftTable::capacity(); i++) {
        if (table[i].valid && isEmergencySquawk(table[i].squawk)) {
            info.active = true;
            strncpy(info.callsign, table[i].callsign[0] ? table[i].callsign : table[i].hex,
                    sizeof(info.callsign) - 1);
            strncpy(info.squawk, table[i].squawk, sizeof(info.squawk) - 1);
            break;
        }
    }
    AircraftTable::unlock();

    return info;
}

}